Final answer:
Gold is a mineral because it is a naturally occurring, inorganic solid with a definite chemical composition and crystalline structure, and has a metallic luster.
Step-by-step explanation:
Gold is classified as a mineral. It is naturally occurring, found in various locations including Ghana, and meets the criteria of being an inorganic solid with a definite chemical composition (Au), and it exhibits a characteristic crystalline structure.
Gold has a metallic luster, indicating that it does not allow light to pass through its atomic structure, which is one of the observable properties used in mineral identification. Furthermore, the way gold has been historically mined in Ghana emphasizes its natural occurrence and the laborious processes involved in extracting it as a valuable resource.